Field of the Invention
The present disclosure relates to a display device. More particularly, the present disclosure relates to a display device which can reduce a bezel width by disposing a sealant which bonds an upper substrate and a lower substrate, to extend to a signal line portion or a gate in panel (GIP) driver.
Description of the Related Art
As a display device, there are a liquid crystal display device and an organic electroluminescence display device configured to include an upper substrate, a lower substrate, where a liquid crystal layer or an organic light emitting device formed between two substrates. The liquid crystal display device is a device which displays an image by adjusting an alignment of the liquid crystal layer depending on whether an electric field is applied to adjust transmittance of light.
Generally, the organic electroluminescence display device (OLED) is classified into a passive matrix type OLED (PMOLED) and an active matrix type OLED (AMOLED) in accordance with a method of driving an organic light emitting device.
The AMOLED includes a plurality of gate electrode lines, a plurality of data lines, a plurality of power lines, and a plurality of pixels which is connected to the lines to be disposed in a matrix. Further, each pixel includes an organic light emitting device configured by an organic light emitting layer between an anode and a cathode and a pixel circuit which independently drives the OLED. The pixel circuit includes a switching transistor which mainly transmits a data signal, a driving transistor which drives the EL element in accordance with the data signal, and one capacitor which maintains a data voltage. The switching transistor charges the capacitor with the data voltage in response to a scan pulse. The driving transistor adjusts an emission amount of the OLED by controlling a current amount which is supplied to the OLED in accordance with the data voltage charged in the capacitor.
A sealant is applied in a seal area which is located in a non-display area (a bezel area) corresponding to an external peripheral portion of a display area of the display device. Therefore, the upper substrate and the lower substrate are bonded.
Recently, in order to satisfy various demands of a user and increase an esthetic sense, an effort to reduce a bezel width of a display device is continuously tried. As a bezel width in the display device is continuously reduced, a size of a seal area for bonding the upper substrate and the lower substrate of the display device needs to be reduced. However, when a width of the seal area is reduced, adhesiveness between the upper substrate and the lower substrate is correspondingly lowered.
In order to implement a narrower bezel width and reinforce the adhesiveness between the upper substrate and the lower substrate, the sealant may extend onto an external signal line formed in a non-display area of a panel and further onto a gate driver. However, some areas of a circuit in the non-display area may be formed of a material whose adhesiveness to the sealant is not strong. Therefore, even though the sealant extends to the circuit portion, the bonding problem between the upper substrate and the lower substrate may be caused due to weak adhesiveness. Further, the circuit unit which overlaps the sealant may be easily damaged by an external force applied to the panel. In this case, a foreign material permeates through the damaged portion to cause problems such as electro-chemical corrosion/corrosion of metal wiring lines. For example, a portion which is formed of ITO in a circuit region which overlaps the sealant not only has bad adhesiveness to the sealant but also is vulnerable to a crack by the external force. As a portion formed of the ITO in the region which overlaps the sealant is increased, a bonding problem of the panel is caused. When a crack is generated in the ITO portion, a permeating path of an external contamination source, such as moisture or salinity is formed to cause an electro-chemical corrosion/corrosion problem of the wiring lines of the panel.
As a result, the seal area needs to be designed to avoid a portion which has bad adhesiveness to the sealant or a portion which is easily damaged by an external force which is transmitted to the sealant. Therefore, there is a restriction to reduce the bezel by overlapping the seal area and the circuit unit.